Known in the art is an internal combustion engine provided with an NOx storage and reduction type catalyst storing nitrogen oxides (NOx) in exhaust gas when an air-fuel ratio of an exhaust is lean and releasing and reducing the stored NOx when the air-fuel ratio of the exhaust is made rich.
WO2014/123232A discloses as such an NOx storage and reduction type catalyst an NOx storage and reduction type catalyst provided with a base member formed with a coat layer on its surface. The coat layer contains a precious metal carried on a support and ceria or a complex oxide of cerium (Ce) and strontium (St) or other Ce-containing oxide. In this NOx storage and reduction type catalyst, when the air-fuel ratio of the exhaust is lean, the NOx in the exhaust is adsorbed at the Ce-containing oxide, while when the exhaust air-fuel ratio is made rich, the adsorbed NOx is discharged from the Ce-containing oxide and reduced.